The present invention relates to a gear pump. More particularly, it relates to a gear pump which has two interengaging gears, an axially movable sealing plate at one side of the gears and pressed against the side surfaces of the latter, and seals which limit the pressure fields at opposite sides of the gears.
Gear pumps of the above mentioned general type are known in the art. In a known gear pump of this type, the sealing plate is brought in sealing contact with the side surfaces of the gears under the action of stepped hydraulic loading of the pressure fields. Thereby the leakage loss between the high pressure and low pressure sides of the machine is maintained at a low level. However, this construction has the disadvantage in that the feeding quantity increases with the increase in the number of revolutions.